[PATCH v3 2/2] compile: Add 'set compile-gcc'

Jan Kratochvil
2015-04-23T21:08:23Z

[-- Attachment #0: Type: message/rfc822, Size: 7784 bytes --]

From: Jan Kratochvil <jan.kratochvil@redhat.com>
Subject: [PATCH] compile: Add 'set compile-gcc'
Date: Thu, 23 Apr 2015 21:39:55 +0200

Hi,

as discussed in
How to use compile & execute function in GDB
https://sourceware.org/ml/gdb/2015-04/msg00026.html

GDB currently searches for /usr/bin/ARCH-OS-gcc and chooses one but one cannot
override which one.

This patch does not change the libcc1 API as it overloads the triplet_regexp
parameter of GCC's set_arguments. GCC decides on the meaning of the
triplet_regexp parameter according to the success of:

+ if (access (triplet_regexp, X_OK) == 0)

Jan

gdb/ChangeLog
2015-04-21 Jan Kratochvil <jan.kratochvil@redhat.com>

* compile/compile.c (compile_gcc, show_compile_gcc): New.
(compile_to_object): Implement compile_gcc.
(_initialize_compile): Install "set compile-gcc". Initialize
compile_gcc.

gdb/doc/ChangeLog
2015-04-21 Jan Kratochvil <jan.kratochvil@redhat.com>

* doc/gdb.texinfo (Compiling and Injecting Code): Add to subsection
Compiler search for the compile command descriptions of set
compile-gcc and show compile-gcc.

include/ChangeLog
2015-04-21 Jan Kratochvil <jan.kratochvil@redhat.com>

* gcc-interface.h (enum gcc_base_api_version): Add comment to
GCC_FE_VERSION_1.
(struct gcc_base_vtable): Describe triplet_regexp parameter overload
for set_arguments.
---
gdb/compile/compile.c | 40 +++++++++++++++++++++++++++++++++-------
gdb/doc/gdb.texinfo | 36 ++++++++++++++++++++++++++++++------
include/gcc-interface.h | 7 +++++--
3 files changed, 68 insertions(+), 15 deletions(-)

diff --git a/gdb/compile/compile.c b/gdb/compile/compile.c
index 7f4c11d..a4ca7db 100644
--- a/gdb/compile/compile.c
+++ b/gdb/compile/compile.c
@@ -299,6 +299,19 @@ append_args (int *argcp, char ***argvp, int argc, char **argv)
(*argvp)[(*argcp)] = NULL;
}

+/* String for 'set compile-gcc' and 'show compile-gcc'. */
+static char *compile_gcc;
+
+/* Implement 'show compile-gcc'. */
+
+static void
+show_compile_gcc (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Compile command GCC driver filename is \"%s\".\n"),
+ value);
+}
+
/* Return DW_AT_producer parsed for get_selected_frame () (if any).
Return NULL otherwise.

@@ -430,8 +443,6 @@ compile_to_object (struct command_line *cmd, char *cmd_string,
int ok;
FILE *src;
struct gdbarch *gdbarch = get_current_arch ();
- const char *os_rx;
- const char *arch_rx;
char *triplet_rx;
char *error_message;

@@ -481,12 +492,17 @@ compile_to_object (struct command_line *cmd, char *cmd_string,
if (compile_debug)
fprintf_unfiltered (gdb_stdout, "debug output:\n\n%s", code);

- os_rx = osabi_triplet_regexp (gdbarch_osabi (gdbarch));
- arch_rx = gdbarch_gnu_triplet_regexp (gdbarch);
+ if (compile_gcc[0] != 0)
+ triplet_rx = compile_gcc;
+ else
+ {
+ const char *os_rx = osabi_triplet_regexp (gdbarch_osabi (gdbarch));
+ const char *arch_rx = gdbarch_gnu_triplet_regexp (gdbarch);

- /* Allow triplets with or without vendor set. */
- triplet_rx = concat (arch_rx, "(-[^-]*)?-", os_rx, (char *) NULL);
- make_cleanup (xfree, triplet_rx);
+ /* Allow triplets with or without vendor set. */
+ triplet_rx = concat (arch_rx, "(-[^-]*)?-", os_rx, (char *) NULL);
+ make_cleanup (xfree, triplet_rx);
+ }

/* Set compiler command-line arguments. */
get_args (compiler, gdbarch, &argc, &argv);
@@ -688,4 +704,14 @@ String quoting is parsed like in shell, for example:\n\
" -fno-stack-protector"
);
set_compile_args (compile_args, 0, NULL);
+
+ add_setshow_filename_cmd ("compile-gcc", class_support,
+ &compile_gcc,
+ _("Set compile command GCC driver filename"),
+ _("Show compile command GCC driver filename"),
+ _("\
+It should be absolute pathname to the gcc executable.\n\
+If empty the default target triplet will be searched in $PATH."),
+ NULL, show_compile_gcc, &setlist, &showlist);
+ compile_gcc = xstrdup ("");
}
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 0410702..cbcc2ee 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -17435,13 +17435,15 @@ will print to the console.

@subsection Compiler search for the @code{compile} command

-@value{GDBN} needs to find @value{NGCC} for the inferior being debugged which
-may not be obvious for remote targets of different architecture than where
-@value{GDBN} is running. Environment variable @code{PATH} (@code{PATH} from
-shell that executed @value{GDBN}, not the one set by @value{GDBN}
-command @code{set environment}). @xref{Environment}. @code{PATH} on
+@value{GDBN} needs to find @value{NGCC} for the inferior being debugged
+which may not be obvious for remote targets of different architecture
+than where @value{GDBN} is running. Environment variable @code{PATH} on
@value{GDBN} host is searched for @value{NGCC} binary matching the
-target architecture and operating system.
+target architecture and operating system. This search can be overriden
+by @code{set compile-gcc} @value{GDBN} command below. @code{PATH} is
+taken from shell that executed @value{GDBN}, it is not the value set by
+@value{GDBN} command @code{set environment}). @xref{Environment}.
+

Specifically @code{PATH} is searched for binaries matching regular expression
@code{@var{arch}(-[^-]*)?-@var{os}-gcc} according to the inferior target being
@@ -17451,6 +17453,28 @@ example both @code{i386} and @code{x86_64} targets look for pattern
for pattern @code{s390x?}. @var{os} is currently supported only for
pattern @code{linux(-gnu)?}.

+On Posix hosts the compiler driver @value{GDBN} needs to find also
+shared library @file{libcc1.so} from the compiler. It is searched in
+default shared library search path (overridable with usual environment
+variable @code{LD_LIBRARY_PATH}), unrelated to @code{PATH} or @code{set
+compile-gcc} settings. Contrary to it @file{libcc1plugin.so} is found
+according to the installation of the found compiler --- as possibly
+specified by the @code{set compile-gcc} command.
+
+@table @code
+@item set compile-gcc
+@cindex compile command driver filename override
+Set compilation command used for compiling and injecting code with the
+@code{compile} commands. If this option is not set (it is set to
+an empty string), the search described above will occur --- that is the
+default.
+
+@item show compile-gcc
+Displays the current compile command @value{NGCC} driver filename.
+If set, it is the main command @code{gcc}, found usually for example
+under name @code{x86_64-linux-gnu-gcc}.
+@end table
+
@node GDB Files
@chapter @value{GDBN} Files

diff --git a/include/gcc-interface.h b/include/gcc-interface.h
index c11b7a1..81925b1 100644
--- a/include/gcc-interface.h
+++ b/include/gcc-interface.h
@@ -46,7 +46,9 @@ enum gcc_base_api_version
{
GCC_FE_VERSION_0 = 0,

- /* Parameter verbose has been moved from compile to set_arguments. */
+ /* Parameter verbose has been moved from compile to set_arguments.
+ Parameter triplet_regexp of set_arguments can be also gcc driver
+ executable. */
GCC_FE_VERSION_1 = 1,
};

@@ -104,7 +106,8 @@ struct gcc_base_vtable

/* Set the compiler's command-line options for the next compilation.
TRIPLET_REGEXP is a regular expression that is used to match the
- configury triplet prefix to the compiler.
+ configury triplet prefix to the compiler; TRIPLET_REGEXP can be
+ also absolute filename to the computer.
The arguments are copied by GCC. ARGV need not be
NULL-terminated. The arguments must be set separately for each
compilation; that is, after a compile is requested, the
--
2.1.0